In 1782, Lapérouse was ordered to undertake a secret mission, which he had helped prepare: to destroy, with a fleet of three ships under his command, the English forts of York and Prince of Wales in Hudson Bay, which protected fur trading posts. Lapérouse, commanding for the first time the vessel Le Sceptre, was accompanied by Fleuriot de Langle, in command of the frigate L’Astrée, and by La Jaille with the frigate L’Engageante. Later, Paul Fleuriot de Langle, a sailor of Breton origin born in 1744, will become the commander of the second ship of Lapérouse for the great voyage in the Pacific.
It was necessary to preserve secrecy in the West Indies filled with spies, hence the obvious under-equipment against the cold. The nautical window of opportunity to enter Hudson Bay is very short between the break-up and the first frosts, with very insufficient nautical charts, although the general shape of the bay is known.
During the battles of Hudson Bay, Lapérouse distinguishes himself not only by his navigational successes, in the absence of precise charts, his military success, but also by his humanistic behavior, respectful of human lives, whether French, English or Indian. Indeed, when he left, Lapérouse left provisions and weapons for the British soldiers left behind, allowing them to wait to be repatriated to England. Among the English soldiers, Lapérouse met Governor Hearn, a great Arctic explorer, whom he respected a lot.